I've been through 10 fieros. . .

They were fun cars and easy to work on and could be made quick for not a lot of cash, which brings you to the main problem. A lot of fiero owners were cheap bastards. The '84s-'87's were decent, but '88 was the year to have (completely redesigned suspension) They started off as bargain commuter cars from GM parts bin/whatever they could grab that was already in production, so expecting them to be fast is asinine. The '89 GT which never made it to production was to come with the 3.4 DOHC motor rated for 240hp (where as the corvette of the same year was rated at 245 yet several hundred pounds heavier) Compare the ride of an AW11 and an '88 and its night and day, those MR2's could cause fillings to pop out.

But for not a lot of dough (under 2k) you can do a SC 3800 swap and have a fun little pocket rocket.

(my first 3800 swap)
Walk+around+on+my+L67+Fiero

Edit: vid of a swapped fiero rolling out
http://www.youtube.com/watch?v=fVAC10YJcY8